Wear-resisting structure



G. P. BARTHOLOMEW.

WEAR RESISTING STRUCTURE.

APPLICATION. EILED JAN- 13. 191 9.

1,330,973, Patented-Feb. 17,1920.

.UNTTED STATES PATENT OFFICE.

GEORGE P. BABTHOLOMEW, OF ESSEX FELLS NEW JERSEY, -ASSIGNOR TO AMERICAN ABRASIVE METALS 00., A CORPORATION OF NEW YORK.

WEAR RESISTING STRUCTURE.

Specification of Letters Patent.

Patented Feb. 17, 1920.

v Application filed January 13, 1919. Serial No. 270,984.

.To all whom it may concern:

Be it known that I, GEORGE P. BAR- THOLOMEW, a citizen of the United States of America, residing at Essex Fells, Essex county, State of New J ersey',"-have invented certain new and useful Improvements in VVear-Resisting Structures, of "which th following is a specification.

My invention relates to the production of wear resisting surfaces for stair treads, floors, car steps and platforms, autoniobile pedals, shoe soles, horse shoe pads and the ike, and comprises an improved type of structure for such uses. It has been heretofore proposed to roduce structures of this kind by embedc ing a granulated or :powdered mass of some intensely hard and refractory mineral such as a ndum or corundum in a matrix of more easily fusible metal, such as cast iron, toform slabs,

strips and panels having a wear resisting surface consisting substantially of the granulated or powdered material referred to, but owing to the weight of the casting and the thickness necessary to make articles by this process, it has been' found unsuitable for manyuses. Moreover such prior structures are very rigid and cannot be made to My invention produces a light and some-' what flexible article and has other advantages evident to those skilled in the art and some of which are hereinafter set out with more or less particularity. The best embodiment of certain forms of my invention at present known to me are illustrated in the accompanying sheet'of drawings in which:

Figure 1 is a crosssection of a wear re- .sisting stair tread applied directly to the supporting staircase or tread.

Fig. 2 is a cross section of a panel embodying my invention provided with a flexible backing or'ba-se, and

a Fig. 3 shows a cross section of a special form of stair tread.

Throughout the drawings like reference characters indicate like parts: 1, represents a composition formed by mixing a quantity of granulated and finely divided alundum, or similar hard material, with a quantity of rubber and the proper proportion of sulfur or other vulcanizing constituent, which composition is deposited in a layer, before vulcanization,-upon the stair tread 2. Care should be taken that the greatest proportion of the alundum should be at or nearest the upper or wearing surface, and the least proportion thereof at the under, or adhering, surface as indicated in the drawing. Conversely the greatest proportion of the rubber compound is at and near the lower surface where its adhesive properties during vulcanization may be directly exerted on the supporting base, and the least proportion in and near the upper surface, there being just enough to hold the alundum )articles. This can be accomplished by making the original mixture of a certain conveniently workable proportion of alundum,- and then, after the layer has been formed, sprinkling an additional quantity of alundum particles in! excess on the surface of such layer and rolling or pressing them in as far as they will go. Also a surface of coarser particles may be added in this latter step, the original mixture comprising finer particles, or the desired localizing of the coarser particles at the wearing surfaces, while any excess of the vulcanizable constituents remains at the attaching surface, may be secured by other means. In any event the object to be attained is the formation of a layer in which the exposed surface shall be a practically continuous body of the alundum or other wear resisting material, while the opposite surface next to the supporting structure has enough rubber in its composition to cause it to'firmly adhere thereto during the vulcanizing process.

When the constituent elements are arranged as above described, and illustrated in the drawing, the whole structure (the stair tread and the superimposed layer) may be i 1 ture so produced is susceptible to vention previously convenient subjected to the action of any suitable vulcaniziiig apparatus. The result is an integral structure all the elements of which are closely knit together, which has a surface highly resistant to wear and which is at the same time slightly resilient, sound absorbent and non resonant.

Another of various possible methodsof attaching to a proper support the strip or panel constituting my invention is illustrated in Fig. 2, where 3, is a strip of canvas or other strong, flexible more or less porous or perforated substance onto which the matrix, with its contained alundum constituting the layer 1,- has been Vulcanized. The under surface of the entire structhe action projecting! of ordinary cements and the edges of the backing strip 3, may be easily nailed or clamped to the supporting base. The form shown in Fig. 1 may be most for some forms of stair treads,

car'steps, automobile pedals, horse shoes and similar structures when the vulcanizing can be done direct? to the supporting body, while that in ig. 2 couldmore easil be employed for flooring, tilin soles and geels for shoes, horse shoe pa s and in other cases where the supporting structure cannot for any reason be present during the vulcanizing step. Thus the form shown in .Fig. 2 could be nailed to a wooden stairway or floor, through the projecting portions of the back 3, if itwas not desired to perforate the material 1.

In addition to the advantages of my inobserved that an important point is the low temperature at which the original layer of loose material may be transformed into the final panel, strip or other ultimate self-. maintaining shape,

recited herein it may be.

as this permits the wear iron matrlx of the prior art structure hereinbefore referred to onto any ordinar supporting structure, and even if possi le, it

would be a costly and difficult operation, while with my invention nearl any char-- acter of supporting material wi l withstand the temperature of vulcanization .without injury, and the rubber and sulfur can be forced into small interstices like the pores of a supporting base, into which molten iron might not penetrate because of the chilling action of the extensive surfaces then ex- 60 posed. p

' In the application to stair treads, my invention because of-its flexibility and'ease of manipulation during the formative process will allow the hard material to be applied to the nosing or outer edge of the tread, which in the case ofa down stairway always wears away first and so becomes slippery and dangerous. such a structure is shown in Fig. 3.

Having described my invention, I claim: As a new article of manufacture a wear resisting panel comprising a self supporting backing and a body of rubber vulcanized thereto, said rubber mineral masses embedded therein and on its exposed surface,

the proportion of mineral matter being greatest at and near the exposed surface and the proportion of ru her being greater near the supporting backing.

- GEORGE P. BARTHOLOMEW.

Witnessesi WM. H. Sam,

ELEANOR C. SEAMAN.

An example of having granulated 

